remoting/codec/video_encoder_vpx.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "remoting/codec/video_encoder_vpx.h"
   6
   7 #include "base/bind.h"
   8 #include "base/command_line.h"
   9 #include "base/logging.h"
  10 #include "base/sys_info.h"
  11 #include "remoting/base/util.h"
  12 #include "remoting/proto/video.pb.h"
  13 #include "third_party/libyuv/include/libyuv/convert_from_argb.h"
  14 #include "third_party/webrtc/modules/desktop_capture/desktop_frame.h"
  15 #include "third_party/webrtc/modules/desktop_capture/desktop_geometry.h"
  16 #include "third_party/webrtc/modules/desktop_capture/desktop_region.h"
  17
  18 extern "C" {
  19 #define VPX_CODEC_DISABLE_COMPAT 1
  20 #include "third_party/libvpx/source/libvpx/vpx/vpx_encoder.h"
  21 #include "third_party/libvpx/source/libvpx/vpx/vp8cx.h"
  22 }
  23
  24 namespace remoting {
  25
  26 namespace {
  27
  28 // Name of command-line flag to enable VP9 to use I444 by default.
  29 const char kEnableI444SwitchName[] = "enable-i444";
  30
  31 // Number of bytes in an RGBx pixel.
  32 const int kBytesPerRgbPixel = 4;
  33
  34 // Defines the dimension of a macro block. This is used to compute the active
  35 // map for the encoder.
  36 const int kMacroBlockSize = 16;
  37
  38 // Magic encoder profile numbers for I420 and I444 input formats.
  39 const int kVp9I420ProfileNumber = 0;
  40 const int kVp9I444ProfileNumber = 1;
  41
  42 void SetCommonCodecParameters(const webrtc::DesktopSize& size,
  43                               vpx_codec_enc_cfg_t* config) {
  44   // Use millisecond granularity time base.
  45   config->g_timebase.num = 1;
  46   config->g_timebase.den = 1000;
  47
  48   // Adjust default target bit-rate to account for actual desktop size.
  49   config->rc_target_bitrate = size.width() * size.height() *
  50       config->rc_target_bitrate / config->g_w / config->g_h;
  51
  52   config->g_w = size.width();
  53   config->g_h = size.height();
  54   config->g_pass = VPX_RC_ONE_PASS;
  55
  56   // Start emitting packets immediately.
  57   config->g_lag_in_frames = 0;
  58
  59   // Using 2 threads gives a great boost in performance for most systems with
  60   // adequate processing power. NB: Going to multiple threads on low end
  61   // windows systems can really hurt performance.
  62   // http://crbug.com/99179
  63   config->g_threads = (base::SysInfo::NumberOfProcessors() > 2) ? 2 : 1;
  64 }
  65
  66 ScopedVpxCodec CreateVP8Codec(const webrtc::DesktopSize& size) {
  67   ScopedVpxCodec codec(new vpx_codec_ctx_t);
  68
  69   // Configure the encoder.
  70   vpx_codec_enc_cfg_t config;
  71   const vpx_codec_iface_t* algo = vpx_codec_vp8_cx();
  72   CHECK(algo);
  73   vpx_codec_err_t ret = vpx_codec_enc_config_default(algo, &config, 0);
  74   if (ret != VPX_CODEC_OK)
  75     return ScopedVpxCodec();
  76
  77   SetCommonCodecParameters(size, &config);
  78
  79   // Value of 2 means using the real time profile. This is basically a
  80   // redundant option since we explicitly select real time mode when doing
  81   // encoding.
  82   config.g_profile = 2;
  83
  84   // Clamping the quantizer constrains the worst-case quality and CPU usage.
  85   config.rc_min_quantizer = 20;
  86   config.rc_max_quantizer = 30;
  87
  88   if (vpx_codec_enc_init(codec.get(), algo, &config, 0))
  89     return ScopedVpxCodec();
  90
  91   // Value of 16 will have the smallest CPU load. This turns off subpixel
  92   // motion search.
  93   if (vpx_codec_control(codec.get(), VP8E_SET_CPUUSED, 16))
  94     return ScopedVpxCodec();
  95
  96   // Use the lowest level of noise sensitivity so as to spend less time
  97   // on motion estimation and inter-prediction mode.
  98   if (vpx_codec_control(codec.get(), VP8E_SET_NOISE_SENSITIVITY, 0))
  99     return ScopedVpxCodec();
 100
 101   return codec.Pass();
 102 }
 103
 104 ScopedVpxCodec CreateVP9Codec(const webrtc::DesktopSize& size,
 105                               bool lossless_color,
 106                               bool lossless_encode) {
 107   ScopedVpxCodec codec(new vpx_codec_ctx_t);
 108
 109   // Configure the encoder.
 110   vpx_codec_enc_cfg_t config;
 111   const vpx_codec_iface_t* algo = vpx_codec_vp9_cx();
 112   CHECK(algo);
 113   vpx_codec_err_t ret = vpx_codec_enc_config_default(algo, &config, 0);
 114   if (ret != VPX_CODEC_OK)
 115     return ScopedVpxCodec();
 116
 117   SetCommonCodecParameters(size, &config);
 118
 119   // Configure VP9 for I420 or I444 source frames.
 120   config.g_profile =
 121       lossless_color ? kVp9I444ProfileNumber : kVp9I420ProfileNumber;
 122
 123   if (lossless_encode) {
 124     // Disable quantization entirely, putting the encoder in "lossless" mode.
 125     config.rc_min_quantizer = 0;
 126     config.rc_max_quantizer = 0;
 127   } else {
 128     // Lossy encode using the same settings as for VP8.
 129     config.rc_min_quantizer = 20;
 130     config.rc_max_quantizer = 30;
 131   }
 132
 133   if (vpx_codec_enc_init(codec.get(), algo, &config, 0))
 134     return ScopedVpxCodec();
 135
 136   // Request the lowest-CPU usage that VP9 supports, which depends on whether
 137   // we are encoding lossy or lossless.
 138   // Note that this is configured via the same parameter as for VP8.
 139   int cpu_used = lossless_encode ? 5 : 6;
 140   if (vpx_codec_control(codec.get(), VP8E_SET_CPUUSED, cpu_used))
 141     return ScopedVpxCodec();
 142
 143   // Use the lowest level of noise sensitivity so as to spend less time
 144   // on motion estimation and inter-prediction mode.
 145   if (vpx_codec_control(codec.get(), VP9E_SET_NOISE_SENSITIVITY, 0))
 146     return ScopedVpxCodec();
 147
 148   return codec.Pass();
 149 }
 150
 151 void CreateImage(bool use_i444,
 152                  const webrtc::DesktopSize& size,
 153                  scoped_ptr<vpx_image_t>* out_image,
 154                  scoped_ptr<uint8[]>* out_image_buffer) {
 155   DCHECK(!size.is_empty());
 156
 157   scoped_ptr<vpx_image_t> image(new vpx_image_t());
 158   memset(image.get(), 0, sizeof(vpx_image_t));
 159
 160   // libvpx seems to require both to be assigned.
 161   image->d_w = size.width();
 162   image->w = size.width();
 163   image->d_h = size.height();
 164   image->h = size.height();
 165
 166   // libvpx should derive chroma shifts from|fmt| but currently has a bug:
 167   // https://code.google.com/p/webm/issues/detail?id=627
 168   if (use_i444) {
 169     image->fmt = VPX_IMG_FMT_I444;
 170     image->x_chroma_shift = 0;
 171     image->y_chroma_shift = 0;
 172   } else { // I420
 173     image->fmt = VPX_IMG_FMT_YV12;
 174     image->x_chroma_shift = 1;
 175     image->y_chroma_shift = 1;
 176   }
 177
 178   // libyuv's fast-path requires 16-byte aligned pointers and strides, so pad
 179   // the Y, U and V planes' strides to multiples of 16 bytes.
 180   const int y_stride = ((image->w - 1) & ~15) + 16;
 181   const int uv_unaligned_stride = y_stride >> image->x_chroma_shift;
 182   const int uv_stride = ((uv_unaligned_stride - 1) & ~15) + 16;
 183
 184   // libvpx accesses the source image in macro blocks, and will over-read
 185   // if the image is not padded out to the next macroblock: crbug.com/119633.
 186   // Pad the Y, U and V planes' height out to compensate.
 187   // Assuming macroblocks are 16x16, aligning the planes' strides above also
 188   // macroblock aligned them.
 189   DCHECK_EQ(16, kMacroBlockSize);
 190   const int y_rows = ((image->h - 1) & ~(kMacroBlockSize-1)) + kMacroBlockSize;
 191   const int uv_rows = y_rows >> image->y_chroma_shift;
 192
 193   // Allocate a YUV buffer large enough for the aligned data & padding.
 194   const int buffer_size = y_stride * y_rows + 2*uv_stride * uv_rows;
 195   scoped_ptr<uint8[]> image_buffer(new uint8[buffer_size]);
 196
 197   // Reset image value to 128 so we just need to fill in the y plane.
 198   memset(image_buffer.get(), 128, buffer_size);
 199
 200   // Fill in the information for |image_|.
 201   unsigned char* uchar_buffer =
 202       reinterpret_cast<unsigned char*>(image_buffer.get());
 203   image->planes[0] = uchar_buffer;
 204   image->planes[1] = image->planes[0] + y_stride * y_rows;
 205   image->planes[2] = image->planes[1] + uv_stride * uv_rows;
 206   image->stride[0] = y_stride;
 207   image->stride[1] = uv_stride;
 208   image->stride[2] = uv_stride;
 209
 210   *out_image = image.Pass();
 211   *out_image_buffer = image_buffer.Pass();
 212 }
 213
 214 } // namespace
 215
 216 // static
 217 scoped_ptr<VideoEncoderVpx> VideoEncoderVpx::CreateForVP8() {
 218   return make_scoped_ptr(new VideoEncoderVpx(false));
 219 }
 220
 221 // static
 222 scoped_ptr<VideoEncoderVpx> VideoEncoderVpx::CreateForVP9() {
 223   return make_scoped_ptr(new VideoEncoderVpx(true));
 224 }
 225
 226 VideoEncoderVpx::~VideoEncoderVpx() {}
 227
 228 void VideoEncoderVpx::SetLosslessEncode(bool want_lossless) {
 229   if (use_vp9_ && (want_lossless != lossless_encode_)) {
 230     lossless_encode_ = want_lossless;
 231     codec_.reset(); // Force encoder re-initialization.
 232   }
 233 }
 234
 235 void VideoEncoderVpx::SetLosslessColor(bool want_lossless) {
 236   if (use_vp9_ && (want_lossless != lossless_color_)) {
 237     lossless_color_ = want_lossless;
 238     codec_.reset(); // Force encoder re-initialization.
 239   }
 240 }
 241
 242 scoped_ptr<VideoPacket> VideoEncoderVpx::Encode(
 243     const webrtc::DesktopFrame& frame) {
 244   DCHECK_LE(32, frame.size().width());
 245   DCHECK_LE(32, frame.size().height());
 246
 247   base::TimeTicks encode_start_time = base::TimeTicks::Now();
 248
 249   if (!codec_ ||
 250       !frame.size().equals(webrtc::DesktopSize(image_->w, image_->h))) {
 251     bool ret = Initialize(frame.size());
 252     // TODO(hclam): Handle error better.
 253     CHECK(ret) << "Initialization of encoder failed";
 254
 255     // Set now as the base for timestamp calculation.
 256     timestamp_base_ = encode_start_time;
 257   }
 258
 259   // Convert the updated capture data ready for encode.
 260   webrtc::DesktopRegion updated_region;
 261   PrepareImage(frame, &updated_region);
 262
 263   // Update active map based on updated region.
 264   PrepareActiveMap(updated_region);
 265
 266   // Apply active map to the encoder.
 267   vpx_active_map_t act_map;
 268   act_map.rows = active_map_height_;
 269   act_map.cols = active_map_width_;
 270   act_map.active_map = active_map_.get();
 271   if (vpx_codec_control(codec_.get(), VP8E_SET_ACTIVEMAP, &act_map)) {
 272     LOG(ERROR) << "Unable to apply active map";
 273   }
 274
 275   // Do the actual encoding.
 276   int timestamp = (encode_start_time - timestamp_base_).InMilliseconds();
 277   vpx_codec_err_t ret = vpx_codec_encode(
 278       codec_.get(), image_.get(), timestamp, 1, 0, VPX_DL_REALTIME);
 279   DCHECK_EQ(ret, VPX_CODEC_OK)
 280       << "Encoding error: " << vpx_codec_err_to_string(ret) << "\n"
 281       << "Details: " << vpx_codec_error(codec_.get()) << "\n"
 282       << vpx_codec_error_detail(codec_.get());
 283
 284   // Read the encoded data.
 285   vpx_codec_iter_t iter = NULL;
 286   bool got_data = false;
 287
 288   // TODO(hclam): Make sure we get exactly one frame from the packet.
 289   // TODO(hclam): We should provide the output buffer to avoid one copy.
 290   scoped_ptr<VideoPacket> packet(
 291       helper_.CreateVideoPacketWithUpdatedRegion(frame, updated_region));
 292   packet->mutable_format()->set_encoding(VideoPacketFormat::ENCODING_VP8);
 293
 294   while (!got_data) {
 295     const vpx_codec_cx_pkt_t* vpx_packet =
 296         vpx_codec_get_cx_data(codec_.get(), &iter);
 297     if (!vpx_packet)
 298       continue;
 299
 300     switch (vpx_packet->kind) {
 301       case VPX_CODEC_CX_FRAME_PKT:
 302         got_data = true;
 303         packet->set_data(vpx_packet->data.frame.buf, vpx_packet->data.frame.sz);
 304         break;
 305       default:
 306         break;
 307     }
 308   }
 309
 310   // Note the time taken to encode the pixel data.
 311   packet->set_encode_time_ms(
 312       (base::TimeTicks::Now() - encode_start_time).InMillisecondsRoundedUp());
 313
 314   return packet.Pass();
 315 }
 316
 317 VideoEncoderVpx::VideoEncoderVpx(bool use_vp9)
 318     : use_vp9_(use_vp9),
 319       lossless_encode_(false),
 320       lossless_color_(false),
 321       active_map_width_(0),
 322       active_map_height_(0) {
 323   if (use_vp9_) {
 324     // Use I444 colour space, by default, if specified on the command-line.
 325     if (CommandLine::ForCurrentProcess()->HasSwitch(kEnableI444SwitchName)) {
 326       SetLosslessColor(true);
 327     }
 328   }
 329 }
 330
 331 bool VideoEncoderVpx::Initialize(const webrtc::DesktopSize& size) {
 332   DCHECK(use_vp9_ || !lossless_color_);
 333   DCHECK(use_vp9_ || !lossless_encode_);
 334
 335   codec_.reset();
 336
 337   // (Re)Create the VPX image structure and pixel buffer.
 338   CreateImage(lossless_color_, size, &image_, &image_buffer_);
 339
 340   // Initialize active map.
 341   active_map_width_ = (image_->w + kMacroBlockSize - 1) / kMacroBlockSize;
 342   active_map_height_ = (image_->h + kMacroBlockSize - 1) / kMacroBlockSize;
 343   active_map_.reset(new uint8[active_map_width_ * active_map_height_]);
 344
 345   // (Re)Initialize the codec.
 346   if (use_vp9_) {
 347     codec_ = CreateVP9Codec(size, lossless_color_, lossless_encode_);
 348   } else {
 349     codec_ = CreateVP8Codec(size);
 350   }
 351
 352   return codec_;
 353 }
 354
 355 void VideoEncoderVpx::PrepareImage(const webrtc::DesktopFrame& frame,
 356                                    webrtc::DesktopRegion* updated_region) {
 357   if (frame.updated_region().is_empty()) {
 358     updated_region->Clear();
 359     return;
 360   }
 361
 362   // Align the region to macroblocks, to avoid encoding artefacts.
 363   // This also ensures that all rectangles have even-aligned top-left, which
 364   // is required for ConvertRGBToYUVWithRect() to work.
 365   std::vector<webrtc::DesktopRect> aligned_rects;
 366   for (webrtc::DesktopRegion::Iterator r(frame.updated_region());
 367        !r.IsAtEnd(); r.Advance()) {
 368     const webrtc::DesktopRect& rect = r.rect();
 369     aligned_rects.push_back(AlignRect(webrtc::DesktopRect::MakeLTRB(
 370         rect.left(), rect.top(), rect.right(), rect.bottom())));
 371   }
 372   DCHECK(!aligned_rects.empty());
 373   updated_region->Clear();
 374   updated_region->AddRects(&aligned_rects[0], aligned_rects.size());
 375
 376   // Clip back to the screen dimensions, in case they're not macroblock aligned.
 377   // The conversion routines don't require even width & height, so this is safe
 378   // even if the source dimensions are not even.
 379   updated_region->IntersectWith(
 380       webrtc::DesktopRect::MakeWH(image_->w, image_->h));
 381
 382   // Convert the updated region to YUV ready for encoding.
 383   const uint8* rgb_data = frame.data();
 384   const int rgb_stride = frame.stride();
 385   const int y_stride = image_->stride[0];
 386   DCHECK_EQ(image_->stride[1], image_->stride[2]);
 387   const int uv_stride = image_->stride[1];
 388   uint8* y_data = image_->planes[0];
 389   uint8* u_data = image_->planes[1];
 390   uint8* v_data = image_->planes[2];
 391
 392   switch (image_->fmt) {
 393     case VPX_IMG_FMT_I444:
 394       for (webrtc::DesktopRegion::Iterator r(*updated_region); !r.IsAtEnd();
 395            r.Advance()) {
 396         const webrtc::DesktopRect& rect = r.rect();
 397         int rgb_offset = rgb_stride * rect.top() +
 398                          rect.left() * kBytesPerRgbPixel;
 399         int yuv_offset = uv_stride * rect.top() + rect.left();
 400         libyuv::ARGBToI444(rgb_data + rgb_offset, rgb_stride,
 401                            y_data + yuv_offset, y_stride,
 402                            u_data + yuv_offset, uv_stride,
 403                            v_data + yuv_offset, uv_stride,
 404                            rect.width(), rect.height());
 405       }
 406       break;
 407     case VPX_IMG_FMT_YV12:
 408       for (webrtc::DesktopRegion::Iterator r(*updated_region); !r.IsAtEnd();
 409            r.Advance()) {
 410         const webrtc::DesktopRect& rect = r.rect();
 411         int rgb_offset = rgb_stride * rect.top() +
 412                          rect.left() * kBytesPerRgbPixel;
 413         int y_offset = y_stride * rect.top() + rect.left();
 414         int uv_offset = uv_stride * rect.top() / 2 + rect.left() / 2;
 415         libyuv::ARGBToI420(rgb_data + rgb_offset, rgb_stride,
 416                            y_data + y_offset, y_stride,
 417                            u_data + uv_offset, uv_stride,
 418                            v_data + uv_offset, uv_stride,
 419                            rect.width(), rect.height());
 420       }
 421       break;
 422     default:
 423       NOTREACHED();
 424       break;
 425   }
 426 }
 427
 428 void VideoEncoderVpx::PrepareActiveMap(
 429     const webrtc::DesktopRegion& updated_region) {
 430   // Clear active map first.
 431   memset(active_map_.get(), 0, active_map_width_ * active_map_height_);
 432
 433   // Mark updated areas active.
 434   for (webrtc::DesktopRegion::Iterator r(updated_region); !r.IsAtEnd();
 435        r.Advance()) {
 436     const webrtc::DesktopRect& rect = r.rect();
 437     int left = rect.left() / kMacroBlockSize;
 438     int right = (rect.right() - 1) / kMacroBlockSize;
 439     int top = rect.top() / kMacroBlockSize;
 440     int bottom = (rect.bottom() - 1) / kMacroBlockSize;
 441     DCHECK_LT(right, active_map_width_);
 442     DCHECK_LT(bottom, active_map_height_);
 443
 444     uint8* map = active_map_.get() + top * active_map_width_;
 445     for (int y = top; y <= bottom; ++y) {
 446       for (int x = left; x <= right; ++x)
 447         map[x] = 1;
 448       map += active_map_width_;
 449     }
 450   }
 451 }
 452
 453 }  // namespace remoting